It seems on my phone its actually the opposite (on 5.0, dont fully know about 5.0.1 yet). It seems my iphone is not doing a good enough job of tracking towers. So i shudder to think how horrible the battery life would be if it performed better.
If im in an elevator or no service area, my phone will show no signal for 5 mins after. theres been times when i've randomly taken the phone out and its showed no signal/searching, so who knows how long its been unable to catch a signal. These are places where i never had issues with the previous iphone.
Alot of times it will also show me i have a 3G connection full bars, but for some reason i wont have data services. i have to turn on off airport mode few times to get it to start up again.
So i'm thinking these are all issues for me atleast with the iphone not doing a good enough job of tracking towers. I remember i had both these problems with my 3gs (searching/3g on but no data) which got fixed at some point but now it seems they're back.